wil6210: fix for memory corruption upon rmmod

Driver disabled PCI master before making sure HW is idle.
This caused memory corruption in case HW access system memory after
PCI master got disabled.
The fix is to change uninit sequence. Make sure FW/HW is idle before
disabling PCI
Signed-off-by: Dedy Lansky <qca_dlansky@qca.qualcomm.com>
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/wil6210/main.c

@@ -20,6 +20,10 @@
 
 #include "wil6210.h"
 #include "txrx.h"
+#include "wmi.h"
+
+#define WAIT_FOR_DISCONNECT_TIMEOUT_MS 2000
+#define WAIT_FOR_DISCONNECT_INTERVAL_MS 10
 
 static bool no_fw_recovery;
 module_param(no_fw_recovery, bool, S_IRUGO | S_IWUSR);
@@ -631,6 +635,9 @@ int wil_up(struct wil6210_priv *wil)
 
 static int __wil_down(struct wil6210_priv *wil)
 {
+	int iter = WAIT_FOR_DISCONNECT_TIMEOUT_MS /
+			WAIT_FOR_DISCONNECT_INTERVAL_MS;
+
 	WARN_ON(!mutex_is_locked(&wil->mutex));
 
 	if (wil->platform_ops.bus_request)
@@ -648,7 +655,24 @@ static int __wil_down(struct wil6210_priv *wil)
 		wil->scan_request = NULL;
 	}
 
-	wil6210_disconnect(wil, NULL);
+	if (test_bit(wil_status_fwconnected, &wil->status) ||
+	    test_bit(wil_status_fwconnecting, &wil->status))
+		wmi_send(wil, WMI_DISCONNECT_CMDID, NULL, 0);
+
+	/* make sure wil is idle (not connected) */
+	mutex_unlock(&wil->mutex);
+	while (iter--) {
+		int idle = !test_bit(wil_status_fwconnected, &wil->status) &&
+			   !test_bit(wil_status_fwconnecting, &wil->status);
+		if (idle)
+			break;
+		msleep(WAIT_FOR_DISCONNECT_INTERVAL_MS);
+	}
+	mutex_lock(&wil->mutex);
+
+	if (!iter)
+		wil_err(wil, "timeout waiting for idle FW/HW\n");
+
 	wil_rx_fini(wil);
 
 	return 0;

drivers/net/wireless/ath/wil6210/pcie_bus.c

@@ -233,8 +233,8 @@ static void wil_pcie_remove(struct pci_dev *pdev)
 	wil_dbg_misc(wil, "%s()\n", __func__);
 
 	wil6210_debugfs_remove(wil);
-	wil_if_pcie_disable(wil);
 	wil_if_remove(wil);
+	wil_if_pcie_disable(wil);
 	if (wil->platform_ops.uninit)
 		wil->platform_ops.uninit(wil->platform_handle);
 	wil_if_free(wil);